一种基于连续星图观测的自旋姿态估计方法

New Method for Attitude Determination of Spin Satellite Based on Continuous Star Map Observation

传统的利用地球敏感器和太阳敏感器作为测量仪器的自旋卫星姿态确定方法存在系统误差和安装误差等,从而导致自旋姿态确定误差较大的问题,文章提出了一种利用星敏感器获取的连续星图估计卫星自旋姿态参数的新方法。该方法以卫星的自旋轴和旋转角速度作为状态变量,通过星敏感器连续跟踪拍摄的恒星的成像位置作为观测量,利用无迹卡尔曼滤波估计出卫星的自旋姿态参数。仿真结果表明,在星敏感器的精度为3″时,该方法的自旋轴估计精度为0.344 8″,自旋角速度估计精度为10-4(°)/s数量级。

Traditional methods for spin satellite attitude determination usually utilize earth sensor and sun sensor as the measurement instruments. The generated system errors and installation error and so on will lead to large spin attitude errors. Considering this problem, a new method using continuous star map acquired by a star sensor to estimate the spin attitude parameters of the satellite was proposed. In this method, the spin axis and the angular velocity of the satellite were used as state variables, and the pixel coordinates of stars obtained through star map matching between adjacent time were used as measurements. The spin attitude parameters of the satellite were estimated by unscented Kalman filter. Simulation results show that with the star sensor accuracy of 3＂, the estimation accuracy of the spin axis is less than 0. 344 8＂ and the estimation accuracy of spin angular velocity is of 10.4 （°）/s magnitude.